Dynamic host configuration protocol (DHCP) is defined by the Internet Engineering Task Force (IETF) in RFC2132. This protocol provides a means whereby a client, such as a mobile computer or the like, may establish a connection with an access node of a communications network. For example, this may be at a wireless hotspot, at a home network, at a university campus or at an Enterprise intranet. Typically a network location awareness process takes place whereby the mobile computer recognizes or identifies the communications network to which it is connected.
Network location awareness (NLA) refers to the ability of a computer or other communications network node to recognize or identify a communications network to which it is connected. For example, network location awareness enables mobile computers to recognize home, work and public networks and wireless hotspots and as a result the mobile computer is able to behave differently depending on which network it is participating in. The mobile computer may use the network information to change settings such as firewall rules, or other parameters.
Unfortunately, some existing network location awareness technology is insecure. For example, in some situations, adversaries are able to cause a computer to believe that it is at a private network and so cause it to use weak security settings, such as opening vulnerable ports at a host firewall. Thus there exists a need to improve security whilst keeping costs down and minimizing the need for adaptations to be made to existing communications network equipment and protocols.